Dynamic characteristics of program execution must be studied in order to calculate meaningful time and parallel processor bounds. The paper entitled "Time and Parallel Processor Bounds for Fortran-Like Loops" [1] studies only the static interaction between statements within a program to arrive at these bounds. Consequently, very loose bounds are obtained for certain programs. Improved estimates of time and processor bounds are provided for two of the example programs presented in the above-mentioned paper. These estimates are based on an expression of the relationship between operations which calculate values and operations which later use those values as operands.

A special purpose computer is described to evaluate the discrete convolution of two sequences of numbers. This computer abandons the traditional model of convolution as a series of inner products which, for input sequences of length n, requires n multipliers and (n − 1) adders to complete a convolution calculation in (2n − 1) time steps. Instead, it is shown that by reorganizing the algorithm, n interconnected processing units are able to evaluate a convolution in n time steps. Each processing unit consists of a multiplier, an adder, and the necessary buffers. In addition to providing increased throughput, the proposed organization results in a highly modular structure with a well defined interconnection pattern.

A computer graphics display system for rapidly shading areas on a raster scan screen is described. With the system, the host computer provides the display controller with the parameters of a set of component trapezoids which cover the area to be shaded. The paper gives an algorithm for use in the host to decompose an arbitrary polygon into component trapezoids and it describes a microcomputer based controller to shade the trapezoids.